All plugin include with our themes with extended license terms like other themes. And our customer has permission to use theses plugins with our themes. Those plugins have some premium features, to use those features user need a regular license.
A user can use any plugin with the regular license for only one site.
If anyone needs those features, they need to purchase the regular license from those plugin authors.For your kind information; we consistently update all existing plugins those are included with our theme whenever we come with our theme update.
So for updated version, you don't need to purchase any plugin separately. But if you want premium features like auto-update, premium content download those can be possible if you buy the single regular license.